Design and Characterization of Low-Power Rectifiers at X-band Using a Low-Barrier Schottky Diode for Wireless Power Transfer Applications

Continued interest in wireless power transfer (WPT) to provide energy in hard-to-reach locations has led to an investigation of a potential X-band WPT system over long distances. These distances lead to low-power rectifier operating points which typically result in very low RF-to-DC conversion efficiencies. Improvements in low-barrier diodes, as seen by ACST’s film-diode products, have shown near thermal-limit responsivity along with extremely low parasitics. The improvement in these parameters result in improved conversion efficiencies at low power levels. This renewed interest and recent improvements compelled a further study into the potential improvements using these low-barrier ACST diodes for X-band rectifiers. This paper discusses the characterization, packaging, and measurements for a rectifier using the ACST 3DSF30 diode, where a measured 9% efficiency for a -20 dBm input represents a 2× improvement over state-of-the-art.